Breast-feeding of newborns and infants has many important medical benefits including enhanced nutrition and immunity to certain illnesses. A mother's breast milk changes with the needs of a growing infant so as to satisfy these health needs of the infant through several development stages. Human breast milk includes immunoglobulins that increase a baby's resistance to many bacteria and viruses. Breast milk is said to inhibit the development of allergies and is rich in protein, sugars, fats, vitamins, and minerals. Recent research suggests that a breast-fed child may have a smaller incidence of ear infections and diarrhea than a non breast-fed child. Moreover, breast-feeding can be very convenient because bottles need not be prepared, transported or cleaned. Breast-feeding also has economic benefits because expensive formulas and bottles need not be purchased.
During breast-feeding an infant "latches on" by taking the entire areola of the breast, or at least a large portion thereof, in their mouth and beginning to suck. The infant's jaws should close around the areola, and not around the central teat or nipple area, which my result in soreness, bleeding and blistering of the nursing mother. By taking a large portion of the areola in their mouth, the infant's gums will form a circular seal and a vacuum on the central nipple area. The infant then stretches and presses the nipple against their palate and squeezes the milk ducts in a rhythmic motion. This releases milk from the lactiferous glands to the milk ducts and ultimately out of several fine holes in the tip of the nipple. Accordingly, some work is required of the infant to receive nourishment during breast-feeding.
Proper breast-feeding, i.e., having the infant "latch on" correctly, may require an extensive amount of training time in which the mother and infant work together to perfect the technique. This learning process is made more difficult when the newborn has been given a bottle or a pacifier. These devices can cause the infant to lick, nibble or chew with their jaws instead of using their tongue to stretch the nipple and apply suction pressure. When proper breast-feeding is achieved, mothers may worry that their baby will forget the proper technique once the baby tries a bottle. Accordingly, due to the benefits of natural breast milk, and due to these training concerns, breast-feeding mothers may be hesitant to allow their infant to try bottle-feeding.
Despite the many benefits of breast-feeding an infant and the many concerns of the mother that their infant may forget the proper breast-feeding technique, many breast-feeding mothers must return to work or otherwise be away from their infant for extended periods of time. In these situations, exclusive breast-feeding is not possible and supplementation with a bottle is needed. Moreover, nursing mothers often must breast-feed their child every two hours for thirty to forty minutes at a time. This can be physically exhausting for the mother. Accordingly, many mothers try to use baby bottles in conjunction with breast-feeding, or switch to bottle feeding altogether. In either case, the infant often will encounter problems during the transition to exclusive bottle-feeding, or with the transition to and from breast-feeding and bottle-feeding when both methods are utilized. When presented with a bottle the infant may refuse to use the bottle because it feels very different from their mother. Use of prior art bottles generally does not ease this transition. Accordingly, even though many women would like to breast feed their infant for several months or even a year, once the infant is introduced to a bottle at several months of age, the infant often will refuse to return to breast-feeding.
Prior art bottles and nipples do not look or feel like a natural breast. These nipples typically comprise an elongate, smooth single rubber nipple piece that has a width much narrower than a natural breast. These prior art nipples allow the infant to apply only suction pressure to the nipple tip to begin fluid flow from the bottle. Moreover, these nipples permit the flow of fluid from the bottle without mechanical pressure applied by the infant. In either case, the fluid is more easily obtained by the infant than during natural breast-feeding wherein the infant must grasp the entire areola in their mouth and simultaneously apply mechanical and suction pressure to the nipple. Accordingly, once the infant is comfortable with bottle feeding the infant will often encounter "nipple confusion" upon returning to breast-feeding.
"Nipple confusion" can be physically painful for the nursing mother because the infant may attempt to breast-feed by grasping only the tip portion of the nipple and therefore not grasping the entire areola in their mouth. In addition, "nipple confusion" can result in frustration to the infant because they may grow accustomed to receiving nourishment without being required to simultaneously apply mechanical and suction pressure to stretch the nipple. The difference between a natural breast and prior art nipples may lead infants to refuse to return to breast-feeding altogether. This may be psychologically and emotionally difficult for a nursing mother that is rejected by her infant who now prefers the "easy" method of bottle-feeding.
Other prior art nipples may include a single rubber piece having a valve positioned therein for preventing the spillage of fluid from the bottle if overturned. These valved prior art nipples present a sanitation problem, however, due to the difficulty of cleaning the inner cavities of the nipple. Moreover, the elongate outer shape of these valved prior art nipples presents the same "nipple confusion" issues as the non-valved prior art elongate nipples.